Cathode ray tube



Nav. 6, 1934. I LUBCKE 7 1,979,392 a cA'rHobE RAY TUBE Filed April 21. 1932 mvENTpR ERNST LUBCKE ATTORNEY Patented Nov. 6, 1934 1,979,392

CATHODE RAY TUBE Ernst Liibcke, Berlin-Siemensstadt, Germany, as-

signor to Siemens & Halske, Aktiengesellschaft, Siemensstadt, near Berlin, Germany, a. corporation of Germany Application April'Zl, 1932, Serial No. 606,570 In Germany May 4, 1931 6 Claims. (Cl. 250-275) In cathode ray-tubes operated with a heated Ode whichis of lenticular shape, that is, like a cathode, it is frequentlydiflicult in practice to concave reflector, is indicated at 21. The emisobtain a sharp spot upon the fluorescent or lumisive surface is made either by the paste or the nescent screen when using high vacuum type distilling process, already well known in the art.

' tubes so that the cathode ray pencil constriction The cathode 21 is heated indirectly by radiaproduced by a gaseous atmosphere must be obtion from a tungsten spiral 22 to which suitable tained in a different manner. heating current is supplied.

The cathodes of the cathode ray tubes used in The cathode is enveloped by radiation-protector the prior art are usually made of wires or ribmeans 23 ,on all sides save the side turned toward -10 bon placed edgewise, and they were predicated the anode. The radiation protection means may either upon purely metallic or an oxide emission be insulated and maintained at a potential of of electrons. By the use of magnetic constrica few bolts negative relative to the cathode tion coils only has it been feasible to secure an potential. optical image of the cathode, that is, the wire or By using a form of cathode and anode as here l5 ribbon, upon the fluorescent or luminescent screen. disclosed the force-lines and thus also the paths In order to obtain a. sharp spot the cathode, of the electrons will be roughly radial and recaccording to the present invention, is so shaped tilinear from the cathode towards the anode. that the cathode rays issuing therefrom will be In the marginal portions of the pencil of rays concentrated and focused to result in a sharp tapered in the direction of the anode, however,

20 spot without outside auxiliary means. The cathforce-lines and thus also electron paths will ode ray pencil or spot is then projected upon arise that are not rectilinear. On the other hand, the fluorescent or luminescent screen by the aid if the cathode and particularly the cathode edge of suitable constriction coils. In order to con are not made correctly, the rays will not concentrate the rays in one spot a cathode of the verge into a focus, but in a somewhat spread 25 reflectoror concave type is used according to this focal line. By changing the angle of aperture invention. The electric-emissive surface of the in the funnel-shaped anode it is possible to cut cathode preferably has the shape of a calotte off such electronic rays as fail to pass rectilinear- (hemisphere) or as a part of a paraboloid. In ly through the apex of the anode. In addition,

' the focus thereof, according to another object and for the same object, the anode may be fur- 00 of this invention, is the open apex of a funnelnished with an annular screen 31 disposed at any shaped anode to which is applied a positive podesired place along the anode funnel. The screen tential which is high compared with the potential 31 extends as far as the wall of the glass vessel in of the cathode, for example, a few hundred order to confine the cathode space relative to the volts. other part of the tube and act as a shield means.

' 35 The foregoing and many other objects and ad- By the constrictive field provided in the rear vantages of the present invention will become apof the anode, the cathode rays issuing from the parent from "a consideration of the following anode funnel along divergent paths are deflected specification and claims in connection with the and are guided in the form of a concentrating ray accompanying drawing which illustrates an expencil through suitable deflector plates or coils -40 emplified embodiment of the basic ideas of the (not shown) to trace any desired pattern upon invention. the. observation screen 6 or upon a suitable photo- Referring to the drawing, the numeral 1 degraphic plate. In order that the shape of the notes the glass vessel of the cathode ray tube profield between cathode and anode may be disvided with a cathode member 2 and the funnelturbed as little as feasible, the constriction coils 45 shaped anode 3. The rectilinear rays issuing are disposed directly in the rear of the anodelOfl from the cathode 2, which are indicated at 5, and are given a small diameter. Under certain are caused to pass through the apex of the ancircumstances it may be of advantage to connect ode 5. After the cathode ray pencil is passed conductively the radiation protector means with through the anode it is subjected to the constricthe cathode in order that also in this manner a 50 tive action produced by the magneticfield set further improvement of the field shape may be up by the coil 4 with the result that a sharply secured to result in a perfectly straight bundle of contoured and focused spot is produced upon the lines between the cathode and the anode giving luminescent or fluorescent screen 6 which coats a sharp focus or spot upon the screen. 7 the inner surface of the tube end wall 7. As a further development-of the basic idea of 55 The electron-emissive body proper of the caththis invention the cathode ray tube may be ren- 11o dered suitable for sound film work by making the emissive surface of the cathode constitute part of a circular or parabolic cylinder. The electronic rays are concentrated into a focal line which is located at right angles to their direction of travel in the apex of the roof-like anode funnel extending in longitudinal direction of the cathode cylinder. The focal line appears upon a film moved past the tube in the form of a strip of light. The width of this strip is varied by acting upon the electron ray pencil by means of an electromagnetic field oscillating at the rate of the audio frequency to be recorded.

In order to regulate the intensity of the produced observable effect upon the screen 6 any suitable means may be used. This may be grid control as shown by Nicolson Patent #1,470,696, or the control may be by variation of the rate of traversal of the fluorescent screen by the cathode ray. pencil, as suggested,.for example, by Rosing Patent #1,16l,734, or by varying the cross section area of the electron stream, as suggested, for example, by Rosing British Patent 25,270 of 1907.

Having now described my invention, what I claim and desire to secure by Letters Patent is the following:

1. A cathode ray tube comprising a cathode member for producing an electron pencil, a coneshaped anode having its apex through which the produced electron pencil is adapted to pass arranged substantially adjacent the cathode,a fluorescent screen upon which the electron penoil is adapted to impinge to produce luminous effects, and a magnetic coil positioned adjacent the base of the cone-shaped anode for producing under the influence of current flowing therethrough a magnetic field to cause a convergence upon the screen of the diverging electron stream issuing from the anode.

12. A cathode ray tube comprising a coneshapedanode member, a curved cathode member having its focus substantially at the apex of the cone-shaped anode member so that electrons .issuing from the cathode are adapted to pass through the apex of the said anode, a fluorescent screen adapted to emit light upon bombardment thereof by the cathode ray pencil issuing from the cathode member and projected beyond the anode, and a magnetic means adjacent the base of the cone-shaped anode for concentrating the electron stream passing through the anode to a sharply defined point upon the fluorescent screen.

3. A cathode ray device comprising a parabolic cathode member for emitting electrons, a, hollow cone-shaped anode member having its apex at the focus point of the parabolic cathode so that substantially all electrons emitted from the cathode pass through the apex of the anode and issue portion of the tube between the anode base and.

the fluorescent screen, and a means for concentrating the electron stream to a sharply defined point upon the screen.

4. A cathode ray device comprising a parabolic cathode member for emitting electrons, a coneshaped anode member having its apex at the focus point of the parabolic cathode so that substantially' all electrons emitted from the cathode Pass through the apex of the anode and issue through the baseportion thereof along a predetermined path, a fluorescent screen in the path of the electron stream projected from the base portion of the anode adapted to become luminescent upon bombardment thereof by the issuing electron stream, and a magnetic means for concentrating the electron stream to a sharply defined point upon the screen.-

5. A cathode ray device comprising a parabolic cathode member for emitting electrons, a coneshaped anode member having its apex at the focus point of the parabolic cathode so that substantially all electrons emitted from the'cathode pass through the apex of the anode and are projected through the base portion thereof along a predetermined path, a fluorescent screen in the path of the electron stream projected from the base portion of the anode adapted to become cathode adapted to emit'a pencil cathode rays,

radiation protection means substantially surrounding the cathode member for causing radiation along a predetermined path, a cone-shaped anode having its apex located substantially at the focus point of the electron stream issuingv from the parabolic cathode, a fluorescent screen adapted to emit luminous rays upon bombardment thereof by the issuing cathode rays, and a V magnetic ray concentrating means interposed between the anode and the screen for concentrate ing the diverging electron stream issuing through the base of the cone-shaped anode to a sharply defined spot upon the fluorescent screen.

ERNST LU'BCKE.

DISOLAI M E R r 1,979,392.-Ernst Litbcke', Ber1inSiemensstadt, German OATHODE RAY TUBE.

Patent dated November f5, 1934. Disclaimer patentee, the asslgnee, Siemens 'ct' Halske, Alcticngesellschaft, assenting.

Hereby in the following words; to wit: I V

"a magnetic coil positioned adjacent the base of the cone shaped anode except where the words are interpreted to read;

envelope and positioned adjacent the "a m etic coil-contained within the tube base 0 the cone shaped anode.

Ofic'ial Gazette July 21, 1936.] I

ed June 16, 1936, by the enters disclaimer to that portion of claim 1 in the specification which is dered suitable for sound film work by making the emissive surface of the cathode constitute part of a circular or parabolic cylinder. The electronic rays are concentrated into a focal line which is located at right angles to their direction of travel in the apex of the roof-like anode funnel extending in longitudinal direction of the cathode cylinder. The focal line appears upon a film moved past the tube in the form of a strip of light. The width of this strip is varied by acting upon the electron ray pencil by means of an electromagnetic field oscillating at the rate of the audio frequency to be recorded.

In order to regulate the intensity of the produced observable effect upon the screen 6 any suitable means may be used. This may be grid control as shown by Nicolson Patent #1,470,696, or the control may be by variation of the rate of traversal of the fluorescent screen by the cathode ray. pencil, as suggested,.for example, by Rosing Patent #1,16l,734, or by varying the cross section area of the electron stream, as suggested, for example, by Rosing British Patent 25,270 of 1907.

Having now described my invention, what I claim and desire to secure by Letters Patent is the following:

1. A cathode ray tube comprising a cathode member for producing an electron pencil, a coneshaped anode having its apex through which the produced electron pencil is adapted to pass arranged substantially adjacent the cathode,a fluorescent screen upon which the electron penoil is adapted to impinge to produce luminous effects, and a magnetic coil positioned adjacent the base of the cone-shaped anode for producing under the influence of current flowing therethrough a magnetic field to cause a convergence upon the screen of the diverging electron stream issuing from the anode.

12. A cathode ray tube comprising a coneshapedanode member, a curved cathode member having its focus substantially at the apex of the cone-shaped anode member so that electrons .issuing from the cathode are adapted to pass through the apex of the said anode, a fluorescent screen adapted to emit light upon bombardment thereof by the cathode ray pencil issuing from the cathode member and projected beyond the anode, and a magnetic means adjacent the base of the cone-shaped anode for concentrating the electron stream passing through the anode to a sharply defined point upon the fluorescent screen.

3. A cathode ray device comprising a parabolic cathode member for emitting electrons, a, hollow cone-shaped anode member having its apex at the focus point of the parabolic cathode so that substantially all electrons emitted from the cathode pass through the apex of the anode and issue portion of the tube between the anode base and.

the fluorescent screen, and a means for concentrating the electron stream to a sharply defined point upon the screen.

4. A cathode ray device comprising a parabolic cathode member for emitting electrons, a coneshaped anode member having its apex at the focus point of the parabolic cathode so that substantially' all electrons emitted from the cathode Pass through the apex of the anode and issue through the baseportion thereof along a predetermined path, a fluorescent screen in the path of the electron stream projected from the base portion of the anode adapted to become luminescent upon bombardment thereof by the issuing electron stream, and a magnetic means for concentrating the electron stream to a sharply defined point upon the screen.-

5. A cathode ray device comprising a parabolic cathode member for emitting electrons, a coneshaped anode member having its apex at the focus point of the parabolic cathode so that substantially all electrons emitted from the'cathode pass through the apex of the anode and are projected through the base portion thereof along a predetermined path, a fluorescent screen in the path of the electron stream projected from the base portion of the anode adapted to become cathode adapted to emit'a pencil cathode rays,

radiation protection means substantially surrounding the cathode member for causing radiation along a predetermined path, a cone-shaped anode having its apex located substantially at the focus point of the electron stream issuingv from the parabolic cathode, a fluorescent screen adapted to emit luminous rays upon bombardment thereof by the issuing cathode rays, and a V magnetic ray concentrating means interposed between the anode and the screen for concentrate ing the diverging electron stream issuing through the base of the cone-shaped anode to a sharply defined spot upon the fluorescent screen.

ERNST LU'BCKE.

DISOLAI M E R r 1,979,392.-Ernst Litbcke', Ber1inSiemensstadt, German OATHODE RAY TUBE.

Patent dated November f5, 1934. Disclaimer patentee, the asslgnee, Siemens 'ct' Halske, Alcticngesellschaft, assenting.

Hereby in the following words; to wit: I V

"a magnetic coil positioned adjacent the base of the cone shaped anode except where the words are interpreted to read;

envelope and positioned adjacent the "a m etic coil-contained within the tube base 0 the cone shaped anode.

Ofic'ial Gazette July 21, 1936.] I

ed June 16, 1936, by the enters disclaimer to that portion of claim 1 in the specification which is 

